Maintaining an efficient irrigation system is a critical way to minimize your water and financial waste while increasing your profits. USDA-NRCS’s New Hampshire State Agronomist Chad Cochrane recently presented on the importance of irrigation efficiency.
In his webinar, he endeavored to introduce growers to the wide range of irrigation options available to them.
As a whole, the efficiency of an irrigation system is based on how the water is being stored, moved and applied to crops. There are generally four basic parts to an irrigation system: a water source, a pump, a series of materials to move the water around (pipelines, filters, pressure regulators, etc.) and the application of the water. Cochrane said, “What we are trying to do that entire [process] is reduce loss.”
Energy efficiency can be improved by properly sizing your pumps and pipes. When choosing a pump size, you must focus on the efficiency of the pump itself, not the engine or motor you’ll use to run the pump. Take into account how much water it needs to hold and how quickly the water needs to move through the pump. “There are lots of different pumps out there, and they must be sized for the task,” Cochrane said.
Similarly, the size of the pipe matters. If the diameter is too small, it will increase friction, increase the work required and wear the pipe quicker.
With warmer weather, water-use efficiency is important to monitor. Doing so reduces water losses from evaporation, runoff and deep percolation, according to Cochrane.
Photo courtesy of Chad Cochrane
The easiest type of water loss to understand is evaporative losses, which increases during hotter weather. Water evaporates through the air and from the soil and plant leaves.
The most efficient irrigation system to reduce water loss is micro-irrigation, watering individual crop rows or plants instead of the entire area of land. This system requires a lower pressure, a lower volume of water and “of the water we are putting out on the field, 90% to 95% is actually being taken up by the plant,” Cochrane said.
Considering you generally water the top layer of soil, keep in mind that gravity will pull the moisture toward plant roots. If you irrigate too much or too quickly, the water will sink past the roots of the crop and be wasted. Using soil moisture sensors to monitor saturation is important.
The two main sensors are volumetric water sensors and water potential sensors. A volumetric water sensor tells you the amount of water in the soil in general, regardless of whether it’s available to plants or not. Water potential sensors tell you how much of the water in the soil is plant-available, which is more useful in most cases.
Either way, the lower the number the sensor shows, the wetter the soil is. There are many ways to monitor and read your sensors, from a handheld reader to a “smart” data logger that sends information to the internet for you to view on your phone.
NRCS offers a few different funding options to help with your farm’s irrigation, including, but not limited to, the Environmental Quality Incentives Program (EQIP) and Agricultural Management Assistance (AMA). EQIP is only used for improving an existing irrigation system, whereas AMA helps reduce finance risks of your irrigation system.
For more information on funding opportunities or to learn more about irrigation efficiency, visit nrcs.usda.gov.
by Kelsi Devolve
